Switch attachment for cameras and the like



Aug. 14, 1934. J T FAGAN SWITCH ATTACHMENT FOR CAMERAS AND THE LIKEFiled June 8, 1932 INVEN TUB. z/bHN TEfi'EAN BY MM w Hrs ATTQRJVE .Y.

Patented Aug. 14, 1934 UNITED STATES PATENT OFFICE LIKE John T. Fagan,Cleveland Heights, Ohio, assignor to General Electric Company; acorporation of New York Application June 8, 1932, .Serial No. 616,061

zclaims.

My invention relates to photography and more particularly to switchingmeans for operation in synchronization with camera shutter movement.Still more particularly, my invention relates to a switching devicewhich can be easily applied to the camera shutter cable release. Whenpictures are taken with the use of flash lamps and the like, the openingof the shutter and the operation of the flash lamp should be properlytimed. This is particularly true when moving objects are to be taken inonly partial darkness and the shutter cannot therefore be opened beforethe illuminant is set off. One object of my invention is to provide aportable switching device for closing an electrical circuit which can beattached to the usual cable shutter 'control and be operated thereby.Various features and advantages of my invention will appear from thefollowing description of a species thereof and from the accompanyingdrawing.

Now referring to the drawing, Fig. 1 is a perspective view of the deviceof my invention; Fig. 2 is a section through said. device: Fig. 3 is aplan view of the body portion of my device; and vFig. 4 is a diagramshowing my device in use. The switch 10 comprises, as shown in thedrawing. a body portion of insulating material such as hardrubber or thelike to which is attached cap 11' by screws ..12 and 13. A raised boss14 forms part of "the cap 11 and receives the head15 of the cablerelease pin 16 which is inserted through opening 17 in the side of saidboss andits tapered portion 18 is held against the edge of opening 19inthe boss by plate 20 of conductive-material preferably metal, which ispressed by spring 21 located between the latter and thebody portion 10of the switch.

Although the. specific shutter release device shown, which is of a wellknown manufacture, is particularly suited for my device, I am aware thatmy device may bemodifled for use with other shutter release devices. Theoperation of the shutter release device is as usual as the release pin16 is now operated by pressure on the switch which takes the place ofits head 15. The electrical function of the switch is brought into playby pressure exerted thereupon after the movement of the release pin 16has been arrestedupon its reaching the limit of its motion as continuedpressure will then force lugs 23 and 24 (Fig. 3) extending from metalterminal straps 25 and 26 respectively into engagement with the plate20. During the fo'repart of the pin motion the switch is not operated asthe resistance of spring 21 is greater than the force required to movesaid pin. The electrical circuit is therefore closed by the bridging ofthe terminals 25 and 26 by the plate 20 after the shutter has beenreleased, and it has been found that such operation allows the shuttoter sufllcient time to be fully opened before the illuminant flashes.Washer 27 serves to insulate cap 11 from. bars 25 and 26. The circuitshown in Fig. 4 includes the switch 10 with its terminals 25 and 26connected respectively to a bat- 66 tery 28 and a flash lamp 29.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A switch of the class described for use with the shutter control pinof a camera, said switch 70 comprising a body portion having a pair ofterminals held therein and having a cap mounted thereon adapted toengage the underside of a head on said control pin and. a conductivemember resiliently mounted with respect to said body in contact with thehead on said control pin and adapted to be pushed into contact with saidterminals by said control pin.

2. A switch of the class described for use with the shutter control pinof a camera, said switch comprising a body portion having a pair ofterminals held therein and having a cap mounted therein adapted toengagethe underside of a head on said control pin, a conductive member adaptedto engage the head of said control pin, and a spring located betweensaid conductive member and said body portion of said switch whereby saidconductive member is caused to' be pressed into contact with saidterminals by said control pin.

JOHN T. FAGAN.

